The MVP battles are going to force voters to think seriously about what it means to be in a pennant race, what is the value of an elite starter vs. a position player, and WAR, what is it good for?

With six weeks left for the main contenders to make their cases, let’s look at the major issues surrounding the MVP chases:

1. There has long been debate about “Valuable” and whether that means a player must be on a contender to vie for this award.

But with the inclusion of first a wild card in each league and now two, the perception of how many teams are contenders has changed.

Historically, if a club was a few games under .500 at this time of year, it was kaput.

However, for example, the Marlins have not been over .500 for nearly two months, yet never have fallen too far out of the race for the second NL wild card.

Three years ago, this same record would have marred Giancarlo Stanton’s candidacy. Now, he is a guy helping a team in a playoff chase.

2. Another longstanding debate is whether pitchers should even be MVP eligible. There have been arguments that pitchers have the Cy Young and shouldn’t nudge in for the MVP, or that a starter who appears in 30 games or a reliever who works mainly one inning at a time should not be competing against position players with 150-plus games.

But this year, in the NL particularly, we are going to have to ask a Clayton Kershaw question. In part, because two of the most obvious candidates — Arizona’s Paul Goldschmidt and Colorado’s Troy Tulowitzki — are out for the season with injuries, so we do not even have to wonder if they could come from losing squads to win this award.

And Pittsburgh’s Andrew McCutchen is on the disabled list with a ribcage injury that is going to threaten his chances for back-to-back MVPs.

When you are injured alters perceptions. Kershaw missed the first month and his candidacy seems relatively unharmed, while McCutchen is missing stretch games and that feels like it is hurting him.

If Stanton were to go down, Kershaw might be the MVP on the “then there was one” theory. But maybe he should be the MVP for the most obvious reason — greatness.

Clayton KershawGetty Images

If you are a Wins Above Replacement devotee, Kershaw actually leads the NL with Stanton second (as calculated by Baseball-Reference.com). The Dodgers had won in each of Kershaw’s past 13 starts (going into Saturday night), a period when the lefty was 11-0 with a 1.16 ERA and .454 OPS against.

The pitching has been so good overall this year that, I think, it has blurred the historic greatness of Kershaw and Seattle’s Felix Hernandez, who also is going to get, at the least, MVP consideration.

3. Well, I was the one who brought up WAR, so I should probably be the one who attempts a take down.

For the record, I like modern stats and admire the attempt to find a metric that incorporates all phases of the game, which is the concept behind WAR (for example, can you put hitting, fielding and baserunning into one formula).

I just feel WAR has significant defects, and blind adherence to it for the vote is as problematic as overvaluing batting average or wins all these years.

As an example, I will use Atlanta’s Jason Heyward. He ranked fourth in the NL in WAR based on being an elite defender and a good-to-very good hitter and baserunner.

Beyond believing WAR over-inflates defensive importance — especially in an age when shifts cover for many defensive flaws — I would encourage my more mathematically blessed brethren to find algorithms that will encompass a fuller offensive picture by incorporating, for example, lefty-righty splits into the formula.

Heyward had the worst average (.165) and OPS (.472) against lefties (minimum 120 plate appearances) of any major leaguer.

No way Heyward compensates enough on defense to essentially give away nearly 25 percent of his plate appearances, no way a guy who should be pinch-hit for in critical late-game situations should be mentioned in the same breath as MVP.

Jason HeywardGetty Images

And this is the moment when my statistically inclined friends might want to cover their eyes.

Because I do believe narrative has to be part of the MVP discussion, and narrative turns objective to subjective.

But I think what is missed is that all stats have a subjective element — someone has to decide what is important to put into the formula and how to weigh it. A stat is only objective because you say it is.

With Heyward — sorry, I don’t mean to pick on you Jason, you are a wonderful player, this is just to make a point—– he had nine homers and 31 extra-base hits. You know who else had exactly those numbers? His fellow Braves outfielder B.J. Upton, who has been getting lambasted for lack of production.

No way Heyward makes up with defense what he is giving away in power. The Braves have the same offensive problems this year as last year — a low batting average and high strikeouts.

But they compensated, to some degree, in 2013 by being fifth in the majors in homers. They are 20th now. That is not all Heyward’s fault. Others on the team such as Upton, Chris Johnson and Andrelton Simmons have underperformed expected power.

But this is where narrative comes in: Atlanta banked on Heyward (literally, giving him a two-year contract) and part of the investment and not spending money elsewhere on power was believing he would bring 20-25 homers and 50-55 extra-base hits.

He cannot fail to honor that and be considered the fourth most valuable player in the league.

4. Can Mike Trout not win the AL MVP? The vote only is supposed to be about this year, but I bet there is sentiment that it is Trout’s time after controversially finishing second to Miguel Cabrera each of the past two years.

Trout was championed, in particular, by the metric crowd. He had, for example, the superior WAR.

Which brings some irony this year, perhaps. Trout again leads the AL in WAR, but just barely over Oakland’s Josh Donaldson.

Traditionalist voters are going to see Trout’s lead over Donaldson in the old-time Triple Crown categories (homers, RBIs and batting average) and give the Angel center fielder the nod.

But if Donaldson overtakes Trout in WAR, do the new-wave voters go with Donaldson and — after all the championing of Trout — actually hurt his candidacy?